ensureTotalCapacityPrecise

If the current capacity is less than new_capacity, this function will modify the array so that it can hold exactly new_capacity items. Invalidates element pointers if additional memory is needed.

Function parameters

Parameters

self:*Self
gpa:Allocator
new_capacity:usize

Deprecated.

Functions

Managed: Deprecated.
AlignedManaged: Deprecated.
Aligned: A contiguous, growable list of arbitrarily aligned items in memory.

Source

Implementation

pub fn ensureTotalCapacityPrecise(self: *Self, gpa: Allocator, new_capacity: usize) Allocator.Error!void {
    if (@sizeOf(T) == 0) {
        self.capacity = math.maxInt(usize);
        return;
    }

    if (self.capacity >= new_capacity) return;

    // Here we avoid copying allocated but unused bytes by
    // attempting a resize in place, and falling back to allocating
    // a new buffer and doing our own copy. With a realloc() call,
    // the allocator implementation would pointlessly copy our
    // extra capacity.
    const old_memory = self.allocatedSlice();
    if (gpa.remap(old_memory, new_capacity)) |new_memory| {
        self.items.ptr = new_memory.ptr;
        self.capacity = new_memory.len;
    } else {
        const new_memory = try gpa.alignedAlloc(T, alignment, new_capacity);
        @memcpy(new_memory[0..self.items.len], self.items);
        gpa.free(old_memory);
        self.items.ptr = new_memory.ptr;
        self.capacity = new_memory.len;
    }
}